This invention is directed to blends of polyamines, ethylenically unsaturated monomers and certain ethylenically unsaturated resins such as vinyl-terminated polyester urethane resins, ethylenically unsaturated polyester resins, and ethylenically unsaturated polyisocyanurate resins, which can be thickened by the addition of polyisocyanates to form polyurea molding compositions which are tack-free within a few minutes. It is also directed to the gelled or thickened unsaturated monomer solutions of these resins which are obtained by the homogeneous intermixing of polyamines and polyisocyanates. It is further directed to a process for the formation of gelled solutions wherein a relatively large molar excess of aromatic polyisocyanate is added to an ethylenically unsaturated monomer solution containing polyamines and one or more of the ethylenically unsaturated polyester, polyisocyanurate or polyester urethane resins. When fully cured by addition reaction between the ethylenically unsaturated components the resulting compositions are surprisingly high in flexural and tensile strength. The molded compositions made from the resins of this invention when mixed with glass and other fillers, pigments, peroxides, mold release agents and so forth can be converted into tractable, tack-free, handleable gels which can be cut into preforms and shaped by either injection or compression molding techniques.